Rediagnosis of the genus Amebelodon (Mammalia, Proboscidea, Gomphotheriidae) , with a new subgenus and species, Amebelodon (Konobelodon) britti
Journal of Paleontology 646: 1032-1040
The diagnosis of the shovel-tusked gomphothere genus Amebelodon has been subject to dispute since it was first established by Barbour in 1927. This dispute stems from a failure to evaluate the phylogenetic nature of two characters found in some specimens referred to Amebelodon: four lophs(ids) on some intermediate cheek teeth (M2 and M1) and internal dentinal rods within the lower tusks. These characters are considered diagnostic for the shovel-tusk gomphothere genera Platybelodon and Torynobelodon, and conflict with the traditional diagnosis of Amebelodon. Newly described specimens of Amebelodon and a detailed morphological analysis of one of the disputed characters, dentinal rods, indicate that the character states in the two shovel-tusker groups are analogous. The genus Amebelodon is rediagnosed to take into account this new information. The rediagnosis of Amebelodon is taxonomically recognized by the designation of a new subgenus, Amebelodon (Konobelodon), which includes all Amebelodon specimens convergent with Platybelodon and Torynobelodon. A new species, A. (Konobelodon) britti, is established that includes all specimens of this subgenus from North America. Specimens from the Moss Acres Racetrack site (Hemphillian) in northern Florida are used in the description of this species.